There have been numerous proposals in recent years for passive vehicle occupant safety belt systems in which a portion of the belt passes through a belt transfer ring. The ring, in turn, is carried by a slider that is driven by a drive device back and forth along a guide rail between a restraint position in which the belt is positioned in a restraint configuration in engagement with the vehicle's occupant and a release position in which the restraint belt is in a release configuration out of the way of the occupant so he or she can enter or leave the vehicle. The belt transfer ring may be associated with a shoulder belt, a lap belt or both a shoulder belt and lap belt. For example, passive systems have been proposed in which the outboard end of the belt is anchored above and behind the occupant, a guide rail is installed generally above vehicle door, and the shoulder belt passes through the belt transfer ring, which is moved with the slider back and forth along the guide rail. Other systems have been proposed in which the guide rail is in the door and a lap belt is transferred between a restraint and release configuration. Various three-point passive systems also employ belt transfer rings. The present invention is suitable for use with many of the systems that are described generally above.
Ordinarily, vehicle manufacturers acquire the components for restraint belt systems from various vendors and receive the components in sub-assemblies or "groups". Each group of components received from the vendor must be manufactured in such a way as to facilitate, to the greatest extent possible, the assembly of the system in the vehicle as it is being built. Probably the most convenient way of installing a passive belt system is to assemble it from two groups of components. The first group, which can be called the "belt group," includes the belts, buckles, retractors, transfer rings and other components that are physically located within the passenger compartment of the vehicle, as distinguished from components that are hidden away in the vehicle body, within the door or in other places which require that they be installed before the finishing and trim elements within the passenger compartment are installed. The latter components make up the "drive-guide group," which comprises either a gear-reduced electric motor or a mechanical motion amplifier for driving the belt transfer ring, the drive wire, the guide rail and the slider.
Inasmuch as the slider is part of the drive-guide group, while the belt transfer ring is part of the belt group, the final connection of the belt group to the drive-guide group has been a cause of considerable trouble, and a satisfactory solution has heretofore not been put forward. In previously known systems, it has been necessary for the drive device to be attached to the vehicle only after interconnection is made between the belt group and the drive-guide group or for the belt to be passed through the belt transfer ring only after the drive device is installed. These limitations in the order of assembly have constituted a significant disadvantage common to many passive belt systems.
The problems described above that are encountered in the initial assembly of the system in the vehicle are also encountered in repairing the system. With presently known arrangements, it is often necessary to disassemble many components of both the belt group and the drive-guide group in order to work on only certain components of one or the other group. Thus, repair procedures involve a substantial amount of time, require special tools and are the cause of considerable inconvenience and expense.